We saw the most amazing thing a few weeks ago: Skocjan Caves in southwestern Slovenia. I apologize in advance because there’s no way I can describe how breathtaking this cavern is, and we weren’t allowed to take photographs inside. Suffice it to say that reaching the cave required a 90-minute bus ride (each way) from Piran, followed by a 5-kilometer hike, and then an entrance fee of $20 per person—and it was worth every bit of that time and expense.
If you’ve been to Luray Caverns or Mammoth Caves in the United States, you’ll have some idea of the fantastical shapes that water dripping through limestone can create over millennia. Huge stalactites and stalagmites that look like melted candle wax; thin hollow straws; long curtains; twisted, pitted columns that resemble coral reefs; wet rippled walls with a sheen like glazed pottery or icing. And the drip, drip, drip of water in the distance (or sometimes on your head) to tell you that the inexorable process is continuing.
Skocjan Caves had all that and something even more remarkable—a torrential underground river running through an unbelievably big gorge. Usually, caves are very still places. Nothing moves. Any pools of water are generally so still that your eyes aren’t sure they’re there (until a drip of water from the ceiling ripples their surface). And there’s no wildlife to be seen, not even bugs. Skocjan begins that way, but halfway through, you start to hear a low rumbling in the background. You’re not really conscious of it, though, because you’re busy marveling at the strange formations all around you.
Eventually, the path through the cave leads to a large opening—you sense that the space beyond it is huge because the lights go far back into the distance, oddly fuzzy. What you don’t realize is that you’re high in the wall of a vast gorge.
As you pick your way down damp, dim stairs, the low rumbling grows louder and louder, until suddenly far below you, in this motionless place, you see a great roaring and rushing of water. A swift brown river is tumbling over rocks, churning up layers of mist that prickle your skin and obscure the lights. The water races between rock walls that twist and turn—as does the metal walkway you follow along the walls (a real feat of engineering). On the opposite wall, you can glimpse old steps cut into the rock face, and from before that, narrow pathways and iron bars set into the rock, which the earliest visitors clung to as they explored this amazing place.
Distances are hard to gauge here, until you remember (from the signs at the visitor’s center) that the metal bridge you’re crossing is 45 meters (nearly 150 feet) above the river, and the roof of the cavern looks at least that far overhead. It feels like the Grand Canyon underground, the sort of otherworldly place where you’d set an Indiana Jones movie or a roleplaying game. Skocjan Caves has been declared a world heritage site—the only one in Slovenia. We’d never seen anything like it. Maybe there isn’t anything else quite like it.
But don’t be tempted to try to run the rapids. Shortly after leaving the cave, the river disappears underground in the porous limestone, to resurface 40 km away somewhere in Italy.